Die-casting machine



May 27, 1930. M. STERN DIE CASTING MACHINE Filed July 16 1928 4Sheets-Sheet.

M. STERN DIE CASTING MACHINE Filed July 16 1928 4 Sheets-Sheet May 27,1930.

May 27, 1930. STERN DIE CASTING MACHINE Filed July 16 1928 4Sheets-Sheet May 27, 1930. M. STERN 1,760,258

DIE CASTING MACHINE Filed July 16, 1928 4 Sheets-Sheet 4 Patented May27, 1930 UNITED STATES PATENT OFFICE MARC STERN, OF FLINT, MICHIGAN,ASSIGNOR TO A C SPARK PLUG COMPANY, OF FLINT, MICHIGAN, A COMPANY OFMICHIGAN nm-cas'rme MACHINE Application filed July 16, 1928. Serial No.292,941.

This invention relates to improvements in die casting machines, andinvolves an automatically operated machine embodying separable diesections, and a melting pot or pressure chamber for molten metal,movable relative to the die sections; the present application being acontinuation in part of pending application for Letters Patent SerialNumber 113,707, filed June 4, 1926.

It is an object of the present invention to provide improved operatingmechanism for moving the cover die and the melting pot and furnace,relative to each other and to the stationary die member, in certainpredetermined relation and concomitantly.

It is a further object of the invention to provide motion transmittingmechanism for the movable melting pot and cover die, which embodies amotion modifying arrangement to cause the melting pot to move to agreater extent and faster than the cover die and which insures the tightclosing of the die members.

Another object is to utilize fluid pressure for ejecting molten metalfrom the pot into the die cavity, the application of which occurs whenthe die members are closed.

A still further object is to provide an improved type of melting potwherein fluid pressure acts directly on the molten metal in the pot toeject the same; the valve controlling the application of fluid pressurebeing arranged so as to relieve the pressure after a charge of metal hasbeen ejected, and the pot being provided with a closure member for anopening through which metal is introduced at regular intervals toreplenish the supply, which closure member is moved ofi the openingbetween each application of pressure, which besides allowing theaddition of metal, serves as a safety factor in relieving pressurewithin the pot and prevents molten metal being drawn into and cloggingthe pressure line or from being splashed out of the pot and causinginjury to the operator.

A further object is to provide the melting pot with a replaceabledischarge nozzle and throat, which will permit the substitution of a newoutlet unit should the one in use become damaged, without tying up themachine for any appreciable length of time or disturbing the remainderof the parts.

Other objects will appear from the following detailed specification,when taken in connection with the accompanying drawings forming a parthereof and illustrating a preferred embodiment of the invention.

In the drawing, Figure 1 is a side elevation of the die casting machinewith certain parts brol'cn away and shown in section.

Figure 2 is a top plan view of the machine.

Figures 3 and 4 are end elevations from opposite ends.

Figure 5 is a detail section view taken on line 5-5 of Figure 1.

Figure 6 is a sectional View of a pressure control valve on line 66 ofFigure 7.

Figure 7 is a sectional View taken on line 7-7 of Figure 6.

Figure 8 is a view of an operating cam element.

Figure 9 is a view showing a sectional cam plate that is secured on theface of the cam element opposite to that shown in Figure 8.

Figure 10 is a section on line 1010 of Figure 8.

Figure 11 is a fragmentary side elevation of the machine, partly insection, and showing one type of melting pot and its associated parts.

Figure 12 is a section taken transversely of the melting pot of themachine shown in Figure 1.

Figure 13 is a transverse section of the furnace or fire box taken online 13-13 of Figure .1.

Referring by reference characters to the accompanying drawing thenumeral 1 indicates the bed or frame of the machine, to the front ofwhich is secured, as by means of L.- shaped bolts or studs 2, asupporting bracket comprising a pair of spaced knees or side portions 3and a bottom cross portion 4. An adjustable screw stud or jack 5 engagesthe bottom cross portion 4 and provides for vertical adjustment of thesupporting bracket. The top surface of the side portions 3 provide atrack or runway for the rollers 6 carried by the platform or carriage 7,whereby the platform may be readily moved back and forth.

Carried by the platform are a number of dependent bolts 8, each carryinga pair of helical compression springs 9 and projecting through a lug 10of the fire box or furnace 11, the springs being located on oppositesides of the lugs so as to resiliently mount the furnace on thereciprocatory platform and relieve it from strains and shocks. The firebox or furnace 11, which may be provided with a suitable burner for fueloil or combustible gas, surrounds and encloses a melting pot orcontainer for casting metal indicatedtat 12, that extends through anopening in the platform 7 and is provided with an annular flange restingon a shouldered portion of the platform at the opening (see Figure 12).Bolted to the top of the platform and overlying the annular flange ofthe melting pot or crucible, are foot portions 13 of a pair of upwardlyextending standards or posts 14, that carry at their upper ends an aircylinder 15. Iteciprocable in cylinder 15 is a piston 16 havlng a stem17 detachably secured by pin 18 in the'head 19 of a rod 20.

The lower end of the rod 20 is secured to the cross head 21 slidable onthe posts 14. A plunger rod 22 having its upper end detachably engagedwith the under side of the cross head 21, extends into a charge cylinder23 into which the molten metal enters through a port 24 and is thendischarged or ejected through the passageway 25 leading to a nozzle,that is brought into communication with the die cavit when the diesections 26 and 27 are close The front section 26 is the movable orcover die, while the die section 27 is stationary or fixed to the frameof the machine, and this latter may be provided with suitablecores andejector devices depending upon the nature of the castings to be made.

Power to move the several parts in timed relation is supplied from someexternal source, as from a continuously operating motor (not shown),that drives a pulley 28-- associated with suitable clutch mechanismenclosed with a case 29 to rotate-the shaft 30, the engagement of theclutch being controlled by a manually operable lever 31. A gear box 32houses suitable gearing for transmitting the rotation of the shaft 30 toa transverse shaft carrying a bull pinion 32, that meshes with a pair ofspaced gear wheels 33 and 34 fixed or keyed on the main shaft 35.Fixedly secured on the end of the main shaft 35 is a crank 36, havingpivoted thereto the end of a link or bar 37 which carries adjacent itsopposite end, a roller 38 that rides on the top surface of a bracket 39upon rotation of the main shaft and consequent reciprocation of the bar.As the throw of the crank 36 approaches its forward limit, the end ofthe bar 37 engages with a lateral pin or projection 40 on the hand lever31, and upon further movement swings the lever forward to disengage orrelease the clutch and thereby throw the machine out of operation. Atthe same time the roller 38 is moved up the inclined surface 41 of thebracket 39 to clear the pin 40, whereby the lever may once more be movedby the operator to effect clutch engagement, it being understood thatone complete rotation of the main shaft actuates the several parts ofthe machine in their proper relation to bring about one complete castingoperation. Obviously, the bar 37 can be omitted if it is desired to havethe machine operate through continuously repeating cycles toautomatically produce one casting after another without'interru'ption.The provision of the bar, however, causes the parts to come to rest atthe same point after the machine has gone through a single cycle of theoperation and enables the operator to remove finished castings from themachine, after which he can again put the machine into operation foranother automatic cycle by swinging the hand lever to engage the clutch.

The inner or adjacent faces of the spaced gear elements 33 and 34 areprovided with complementary cam grooves, such as shown at 45 in Figure8, and a swinging lever 46 pivoted on the frame of the machine at 47 andpositioned between the gear wheels, carries on opposite sides thereof, apair of antifriction rollers that project into the cam grooves and causemovement of the lever to and fro upon rotation of the gear wheels. Thepin 48 at the upper end of the lever 46 serves as a pivotal mounting fora yoke member 49 and a pair of links 5050. The yoke member 49 has ascrew threaded stem 51 that carries a cushion or buffer 52, preferablyconsisting of a block of rubber or other elastic material, andprojectsthrough and is secured by nuts -53 to a cross bar 54. To support theWeight of the bar and permit its to and fro movement, the link 55pivoted at 56 to the frame 1 and at 57 to the cross bar has beenprovided. Tie rods 58 connect the cross bar with the carriage orplatform 7 to impart the movement of the lever 46 directly thereto. Theelasticity of .the cushion 52 serves to maintain a tight fit of themelting pot nozzle in the sprue opening of the cover die and tocompensate for slight irregularities such as would be caused by relativeexpansion of v above and low the rod 61, the pin 66 extending verticallythrough the rod serving -to pivotally mount the plates 67 and 68 there-1 and 2, swings the toggle link and tends tov straighten out the links69-71 and 70-72, whereby the force of the movement is greatly increasedand the tight closure or clamping together of the die sections isinsured. At the same time, of course, the extent of movement is cut downand since the platform carrying the furnace and melting pot is di--rectly connected with the swinging lever, its movement will be morerapid and of greater distance. Therefore, the relation of the movementis such that the discharge nozzle of the melting pot moves entirely awayor free from the cover die as the die sections separate, the rate ofmovement of the nozzle in relation to the rate of movement of the coverdie section, being greatest during the initial opening movement, as wellas during the final closing movement of the die sections.

Mounted on the outer side or face of the gear element 33, as by means ofdowel pins, is a cam element 75, which for convenience and economy ofmanufacture may be formed in two halves. as shown in Figure 9.Projecting into and riding on the surface of the cam groove 76 is ananti-friction roller mounted on a bell crank 77 that is connected bylink 78 to an arm 79 fixed on a rock shaft 80. The arm 81 fixed on theend of the rock shaft 80 is connected by a tie rod 82 with the arm 83 ona shaft 84 carrying the valve member 85 within the housing 86. The valvemember 85 has two positions of adjustment to which it is moved by theengagement in the cam groove 76 of the roller on the bell crank 77during a rotation of the mainshaft. In the position shown in Figures 6and 7, air or other suitable fluid under pressure, supplied from apressure tank 87 thru the conduit or pipe 88, enters the space orchamber 89 in the valve casing and passes through an opening 90 in thevalve member 85 that is in communication with a chamber 91 connected bya flexible hose or conduit 92 with the cylinder 15 below the piston 16.The pressure tends to force the piston upward and as the piston risesthe air above the same will escape'through the flexible'hose or conduit93 connected with a chamber 94 in the valve housing, which chamberatthis time communicates with a groove 95 in the valve that is open tothe atmosphere at all times through the mediumof a chamber 96 and pipe97. In the other position of the Valve member 85, the opening 90 isbrought into alinement with the chamber 94 and the groove 95 places thechamber 91 in communication with atmosphere, whereby the fluid underpressure acts on the top side of the piston and the space below thedescending piston is vented.

The operators station is beside the machine close to the parting line ofthe die. To put the machine through its operatin cycle he throws thehand lever 31 toward t e rear of the machine to engage the clutch andset in motion the main shaft 35 which carries the several cams that areso arranged as to actuate the various parts as heretofore referred to inpredetermined sequence. That is, the lever 46 is swung rearwardly movingthrough the toggle mechanism, the cover die section toward and intoclosed relation with the stationary die section and shifting thecarriage 7 through its direct connection with the lever to bring thedischarge nozzle into communication with the sprue opening in the coverdie, that extends at right angles to the parting line of the diesections. At this time the valve 85 is actuated by its cam to admit airunder pressure on the upper side of the piston 16 forcing down theplunger 22 to eject molten metal from the pot into the die cavity, thelever 46 during this time being held stationary at its rearmost limit byreason of-cam contour. Continued rotation of themain shaft 35 andmovement of the cam 7 5 actuates the valve 85 to direct air underpressure to the underside of the piston 16 to restore the plunger 22.After the die cavity has received its charge, the melting pot nozzle ismoved away from the cover die with the forward swinging of the lever 46which swinging movement also separates the die sections. As the mainshaft 35 nears-the end of one complete rotation, the crank 36 pushesforward on the rod 37 which engages the pin 40 and throws the lever 31to automatically disengage the clutch and stop the machine. The operatormay then remove and inspect the completed casting and the machine isready for a repeat cycle.

Thus it will be seen that engagement of the clutch mechanism effects anautomatic operation of the machine through a given cycle, the poweracting through the gear train, cam elements and linkage to open andclose the die members, move the furnace and melting .pot relative to thedie members and reciprocate the plunger to force a charge of moltenmetal into the die cavity, all in proper timed relation.

The melting pot or crucible embodying. the plunger and charging cylinderis especially adaptable for use with low temperature casting metals suchas tin, lead and zinc. However, there are certain metals, such asaluminum, that require the direct application of fluid pressure thereonbecause of their great corroding tendencies on plungers, and thearrangement illustrated in Figure 11 is particularly intended for usewith such metals. In this case, the gear element 34 may be provided onits outer face with a plate 100, corres onding' to the arrangement ofthe plate 5 and gear element 33. A bell crank 101 may be provided withan anti-friction roller for projection into the camgroove 102 in theplate 100, to swing the same upon rotatransmitted by the'link 103 to abell crank 104 connected by a rod 105 with a lever 106 pivoted at 107 onthe valve housing 108. Enclosed within the housing 108 are a 'pair ofvalves 109 and 110, having stems pro ecting from the housing which carrycompressionsprings 111 and 112 respectively that tend to seat thevalves. The swinging movement of the lever 106 to the position shown inFigure 11 causes it to bear on the stem of the valve 109 to open thevalve against the pressure of its spring and allow the fluid underpressure to flow from the pressure line 113 through the flexible hose114 to the top of the melting pot115. where it acts on the molten metaltherein to force the samethrough the outlet passageway 116 and dischargenozzle communicating with the cavity in the die members. When the lever106 is swung in the opposite direction the valve 109 moves to closedposition and the valve 110 is opened to relieve the pressure by allowingthe air or other fluid to escape to atmosphere. In place of the plungerpreviously described, there is substituted a valve or closure member 117for an opening 118 in the top of the melting pot. Reciprocation of thepiston 16 in the cylinder 15, in this instance, opens and closes thevalve 117 in accordance with the application of pressure on the contentsof the melt ing pot. The purpose of the valve or closure member istwofold. First, it allows the introduction into the melting pot ofingots or additional metal to replenish the supply, and, second, itsupplements the action of the valve 110 in relieving pressure after acharge of metal has been ejected. This latter is intended as a safetyfactor to prevent injury to workmen by splashing of hot metal afterdischarge nozzle moves away from the die sections, in event the pressureis not entirely relieved by the opening of the valve 110, or.

in case some of the metal should be splashed or-drawn into thepassageway of the hose fitting in the top of the melting pot and thereby'clog the same.

It will be noted that the discharge passageway 116, instead of beingformed in an integral part of the melting pot as has heretofore een thecustom, is provided in a replaceable unit removably secured to themelting pot by one or more studs or bolts 1 20 and which comprises thenozzle 121 and dependent extension or throat 122. This arrangement isfound to be particularly advantageous in that it permits readyreplacement of the unit in the event of damage due to corrosion orotherwise, without disturbin j the furnace or melting 0t and associateparts. Furthermore, it eliminates the neces: sity for the user to keepon hand a number of spare melting pots to take care of such emergencyand thus materially reduces oper- I ating costs and saves storage space.

In certain cases where the size of the castings call for comparativelylarge die members it may be found desirable to employ a pair ofconnecting rods 64 at each side of the bearing block in verticallyspaced relatype of work on hand. Each pair of vertically spaced rods ispreferably connected to a cross bar 124 provided with a screw threadedstem 125 extendin thru the cross bar 63 and secured thereto %y thead'ustable nuts 126. Thus the adjustment of our connectingrods will besubstantially the same as for two, and much difficulty in efl'ecting theproper alignment of the die section is avoided.

While the die casting machine forming the present subject matter hasbeen described more or less specifically, it is'to be understood thatthe invention is not limited to the exact details shown, but that suchmodifications may be made as come within the scope of the appendedclaims.

I claim:

1. In a die casting machine, a movabl melting pot member, a movable diemember movable in the path of movement of said pot member, means commonto said members to concurrently move them thru the same path,connections between said means and the respective'members, one of theconnections including a motion modifying device, whereby the concurrentmovement of the members is thru different limits.

2. In a die casting machine, a stationary die member, a movable coverdie member having a sprue opening extending from a point spaced from theparting line, a melting pot movable relative to said movable die memberin the plane of movement-thereof to bring its discharge nozzle into orout of engagement with said sprue opening, a work performingmembeflmovable in reverse directions as a part of the operating cycle ofthe machine, a direct connection between said work performing member andone of said movable members, and a toggle link connection between thework performing memberand the other of said movable members, wherebythey are simultaneously moved thru means associated with the directconnection.

4. In a die casting machine, a movable die member. a movable containerfor the casting material movable in the path of movment of the diemember, operating means common to said movable parts, a motion modifyingconnection between said means and the die member, and a directconnection between said means and the container, whereby they aresimultaneously moved in the same path at different rates.

5. The structure of claim 4, wherein a resilient expansion compensatingmeans is associated with the connection between the operating means andthe container.

6. In a die casting machine, a stationary die member, a movablecontainer for the casting material, a movable die member interposedbetween the stationary die member and the container and movable in thepath of the container, operating means common to said movable parts tomove them concurrently, and a toggle link connection between said meansand the die member to vary its rate of movement relative to that of thecontainer.

7. In a die casting machine. a stationary die member, a movable coverdie member, a melting pot movable relative to and in the plane ofmovement of said cover die member, a work performing member, movable toand fro as a part of the operating cycle of the machine. a connectionbetween the work performing member and the melting pot and a connectionbetween the work performing member and cover die member, one of saidconnections including a motion modifying device to differentiate themovement of the cover die and pot.

8. In a die casting machine, a rotating cam element, a swinging leverhaving a part engageable n th the cam element, a movable container forthe casting material and a movable die member, each having an operativeconnection with said swinging lever, the connection between the leverand die member including a motion modifying device.

9. In a die casting machine, the combination with a statioary diemember, a movable cover die member and a container for casting materialmovable relative to said cover die member, of operating means for saidparts including a cam element, a member engage-able with said camelement for to and fro movement and connections between said member andthe cover die and the container respectively, the connection with thecover die including a set of toggle links.

10. In a die casting machine. the combination with a melting pot movablerelative to a die member, of a closure cap for an opening in said pot, afluid pressure actuated device includin a cylinder and piston, means tointroduce" uid under pressure to either of the opposite sides of thepiston to open or close said cap, a valve controlling the application ofpressure on opposite sides of the iston, a valve controlling theapplication of pressure on the contents of said pot to eject the same,and pair of cam elements rotatable in unison and having cam grooves inthe opposite faces thereof, an operative connection having engagement inthe cam grooves in the adjacent inner faces of said cam element, formoving said melting pot and oper ative connections governing theoperation of said valves having engagement in the cam grooves in theouter faces of said cam elements.

11. In a die casting machine, a movable die member, an operating elementtherefor, two pair of connecting rods secured at one end to the diemember, and means to adjustably connect the opposite ends of the bars tothe operating element including a connecting member common to the barsof one pair and a second connecting member common to the bars of theother pair, each of said members being independently adjustable.

12. In a die casting machine, a stationary die section, a movable coverdie section having a sprue opening extending therethrough at an angle tothe parting line of the die, a melting pot movable relative to and inthe plane of movement of the cover die to bring its discharge nozzleinto and out of communication with said sprue opening, and areciprocatory operating member for both the cover die section and themelting-pot, having independent connections with the cover die sectionand melting pot, one of which connections includes a motion modifyingdevice to differentiate the movement of the pot and die.

13. In a die casting machine, a stationary die section, a movablemelting pot, a cover die section interposed between the stationary diesection and the pot and movable relative to the stationary die sectionand to the pot in the plane of movement of the pot, an actuating membermovable first in one direction and then in a reverse direction as a partof the machines operating cycle, a direct connection between said memberand the pot and a toggle connection between said member and the diesection, whereby the movement of the pot is faster and to a greaterextent than that'of the cover die section.

14. In a die casting machine, a fixed die, a

cover die movable in a horizontal plane to and from the fixed die, amolten metal container movable in a horizontal plane to and from thecover die, and an actuating member common to the cover die and containermovable in reverse directions as a part of the operating cycle of themachine to open and close the die and bring the .container into and outof communication with the die cavity.

15. Inufdie casting machine, astationary die section, a movable diesection interposed between the pot and stationary die section, areciprocatory actuating member for simultaneously moving both themelting pot and the movable die section, motion transmitting means forthemovable die section including a bell crank connected thru one legwith the actuating member and thru its other leg with the die section'a'nd at an intermediate point adjacent'the apex of the angle between itslegs with a part of the frame.

, 16. In a die casting machine, a frame, a

die section carried by the frame, a movable I cover die, means movablycarried by the frame to support the cover die, an actuating membercontrolling the movement of the cover die, a pair of bell cranks, eachpivoted at one end to the actuating member, a pair of links associatedwith each bell crank, one link of each pair being pivoted at oppositeends to said supporting means and the opposite end of its adjacent bell,crank respectively and the other link of each pair being pivoted atopposite ends to the frame and an intermediate portion of its adjacentbell crank, a molten metal container movable relative to the cover die,and a direct connection between said actuating member and the container,whereby movement of said actuating member moves both the cover die andthe container but at different speed and to different extent.

17. In a die casting machine, a frame, a die section carried by theframe, a movable cover die, means movably carried by the frame tosupport the cover die, an actuating member controlling the movement ofthe cover die, a pair of bell cranks, each pivoted at the end of one ofits angular legs to the actuating member, a pair of toggle linksassociated with each bell crank, one link of each pair being pivoted atends to said supporting means and the opposite end of the other leg ofits adjacent bell crank respectively and the other link of each pairbeing pivoted at oppo site ends to theframe and an intermediate portionwith the apex of the angle between its legs of its adjacent bell crankwhereby the cover die is forcibly moved thru the combined multipleaction of the bell cranks and toggle links.

18. In a die casting machine, a movable die carrier, an actuating membertherefor, a bell crank'having one leg pivoted at its end to said member,a swinging link having a fixed pivot at one end and a pivotal connectionat its other end with an intermediate portion of the bell crank at theapex of its angular legs, and a second link having pivotal connectionsat opposite ends with the end of the other leg of the bell crank andsaid carrier respectively.

19. In a die casting machine, a movable die carrier an actuatingmembertherefor, a lever ivote at one end to said member, a pair of linkspivotally connected at adjacent ends with said lever at oints spacedfrom each other and from the rst mentioned pivot, and at opposite endswith a fixed part and said carrier respectively. 20. In a die castingmachine, a fixed die, a movable cover die, a support for the cover die,a series of reciprocatory bars carrying said support, and a bearingblock having a series of guides therein for the bars and in which I thebars may be interchangeably mounted in different relations toaccommodate dies of varying sizes and shapes.

In testimony whereof'I aflix my signature.

. MARC STERN.

